Heretofore, in a cup type automatic vending machine for selling regular coffee and the like, after money such as coins and bills or a card such as a prepaid card (to be referred to as "money" hereinafter) has been inserted into the automatic vending machine and a product selection button has been depressed, coffee for one cup has been extracted and sold. However, since a waiting time for each sale is several tens of seconds with this system, a large number of customers cannot be handled at a time.
In recent years, there has been developed a cup type automatic vending machine of a system that a predetermined amount of coffee is previously made and stored in a storage tank at a peak time zone and supplied from the tank each time money is inserted and the product selection button is depressed. The automatic vending machine of this system is disclosed by Laid-open Japanese Patent Application No. Hei 1-237899. Employing this system, the waiting time is shortened to 10 seconds or so.
In this automatic vending machine, a built-in main control unit estimates sales of each day and as a result, extraction and storage operations are started a little before the estimated peak time zone. The sales estimates are made by recording the type of a product and a time each time a product is sold and keeping this record for a predetermined number of days so that information on which products and how many cups will be sold at what time zone of the day are estimated based on the sales information.
However, since sales estimates are made by each automatic vending machine in the above technology of the prior art, the prior art has a problem such that sales which is the primary operation of the automatic vending machine is interfered because of the large burden of processing the data. Further, since it is necessary to store a huge volume of sales information for making sales estimates for each of a wide variety of products, a large-capacity memory is required for each automatic vending machine, thereby boosting costs.
It is therefore an object of the present invention to solve the above problem, lighten the processing burden of each automatic vending machine for sales estimates and eliminate the need for a large-capacity memory.